Mechanically moved grate



June 9, 1936. B. TELGMANN 2,043,719

' MECHANICALLY MOVED GRATE Filed Au 1:5, 1931 2 Sheets-Sheet 1 June 9; 1936. 2,043,719

' MECHANICALLY MOVED GRATE Filed Aug. 13, 1931 2 Sheets-Sheet 2 Patented June .ii, 1936 I z,o43*,719

mtcnamomrmovnn Guam Bernhard'l'elgmann. Dortmund-Bare Germany Application sum 1:, 1931, Serial No. 556,867 In Germany January 16, 1929 'tcwm (c1. u'c-aa) lhe invention relates to mechanically moved I grates and has for its purpose to attain a better breaking up, burning and conveying of the fuel layer on the grate than performed by the hitherto used grate constructions.

For this purpose according to the present invention a grate is used which is freely supported on elastic means in an approximately horizontal position and intermittently driven in an approximately vertical direction. In consequence thereof upwardly and downwardly directed thrust movements having a slight horizontal component are imparted to the whole grate and reinforced by the elastic mounting. By this means the fuel layer is constantly thrown up from the grate, describes short parabolae directed towards the rear end of the grate and falls down again on the grate. Due to 'this movement the fuel is looscried and broken up so that it cannot form socalled cakes; at the same time the fuel is mixed intimately'with the combustion air and conveyed- 0n the grate so that a constant and thorough combustion is attained. Furthermore, the flue-gases are set into pulsating motion, whereby the heat transmission to the boilers is improved. Also, the grate bars are at times completely free from the fuel and may be cooled by the surrounding combustion air, and a choking-up of the grate is avoided.

For the elastic means which support the driven grate in the described manner the invention preferably uses semi-elliptic plate springs certain I of the ends of which are rigidly secured to supports. of the grate bars while their other ends are loosely connected by links to these supports. The plate springs are in their turn mounted on a fixed support at points between their ends.

For driving the grate in the described manner the invention preferably uses eccentric means.

.These means may consist of a regular eccentric or of oscillating eccentric bodies which rotate in an inverse sense in such synchronism that they swing in their vertical position in the same direction and in their horizontal position in op- I posite directions. In consequence thereof the. centrifugal force of the oscillating bodies is annulled .in the horizontal direction by'their counthe clinker.

moved by the grate itself into the clinker hopper Fig. 2 is an elevation of another form of the grate.

Fig. 3-is anelev'ation of quite another form of r the grate.

Fig. 4 is a front view of a longitudinallysubdi- 5 vided grate. I

Fig.'5 is an elevation of a somewhat modifiedform of the invention.

Fig. 6 is a cross-section according to Fig. 5.

In Fig. 1 the steel grate bars a are arranged on bulb irons cwhich are secured to the longitudinal supports d. The supports (1 rest in an approximately horizontal position slightly inclined I towards the rear end on the semi-elliptic plate springs I which are rigidly secured with their 1 front ends to the supports (2 and loosely connected to the same'at theirrear ends by means of links a. which are pivoted at y in the spring end and at z in the supports (1., The grate is balanced by these springs, i. e. the springs are so dimensioned and adjusted that the grate if provided with a normal layer of fuel rests in its middle position.

If the grate is moved upward and downward on the plate springs the front connecting point of. the latter with'the longitudinal supports describes approximately a short curve around the middle supporting point on the fixed transverse supports g as the centre.

By means of an eccentric e which is keyed on to a-rotatable shaftan upward and downward oscillating movement having a slight horizontal component is imparted to the grate which movement is reinforced '-'by the spring mounting so that the fuel is constantly thrown upward and conveyed to the rear in accordance with the process 'of combustion.

The fuel is fedto the grate by the coal hopper h on which a regulating slide it is arranged. In order to ensurea orm feeding a plate i,is hinged on to the coal hopper as shown in Fig. 1 and rests with its lower end on the oscillating grate so that it participates in the movement of the grate, whereby the fuel is uniformly shaken At the end of the grate a clinker grate is arranged, the bars b of which are connected atthe front end with the grate frame or longitudinal supports d like the grate bars a and rest at the .rear end on a transverse support 1: which is adjustable in height for regulating the removal of The linker grate therefore banks up the. fuel layer m re or less sothat a uniform thickness of the fuel layer is maintained without a special device. In this way the clinker is resheets u which can slide one over the other, the

top sheet being firmly connected with the support t.

Fig. 1 shows furthermore a subdivision of the grate into zones which are formed by the metal sheets 3) and the hoppers'q arranged between the longitudinal supports d.

Fig. 2 shows provision of two grates, instead of the one grate shown in Fig. 1, arranged one behind the other like step grates and operatively connected by a fixed grate n. a are the bars and d the supports of the grates which are supported on the plate springs I mounted on supports g in the like manner as in Fig. 1. 'e are the eccentrics for moving the grates in the indicated manner. Instead of the plate 11 of Fig. 1 an inclined grate Z is used. The metal sheet which is connected with the front grate forms an oscillating chute which catches the fuel falling through and conveys it to the second grate. In order to ensure a big grate area several grate steps can be arranged in the manner shown onebehind the other. The arrangement in steps also ensures that any fuel cakes possibly formed on the first step are broken up while being transferred to the second step. The remaining parts of the arrangement shown in Fig. 2 which correspond with those shown in Fig. l, are designated by the same reference characters. i

Fig. 3 shows a preliminary or supply grate of the same construction as the first grate in Fig". 2 in connection with a movable grate w. In the same way the grate can be arranged in front of any other desired type of grate. Instead of the inclined grate Z of Fig. 2 a step grate Z is used. The remaining parts shown in Fig. 3 which correspond with those shown in Figs. 1 and 2, are designated by the same reference characters with. the index 2 added.

In the last two forms of construction (Figs. 2 and 3) the first step i. e. the preliminary grate is slightly inclined towards the front end, whereby the fuel is banked up. This and the radiation of v the fire gases which moveupwardly ensure a good ignition of the fuel entering from above.

The grate a can be constructed in any desired width as a unit or longitudinally subdivided in several grates as shown in Fig. 4, the eccentrics or other driving devices e of which may be displaced in relation to one another in a suitable manner. This arrangement ensuresthat the fuel layer is constantly broken up in a transverse direction.

' In Figs. and 6 a somewhat modified construction of the grate according to Fig. 1 is shown. Besides the supports I of the grate bars which supports are elastically mounted on semi-elliptic plate springs l l in the same manner as in Fig. 1, lower supports 3 are provided below the supports land rigidly connected with the same by bars 2 or the like. On the lower supports two shafts 4 and 5 are mounted, which are connected with one another by two intermeshing gear wheels 6 which are alike. The front shaft 4 is driven by an electromotor 8 by means of a flexible shaft 1 (Fig. 6), the motor being provided with an adjustable revolution regulator.

On the front shaft 4 two eccentric masses 9, and-on the rear shaft two eccentric masses l 0 are keyed in such a position that when the shafts connected by the gear wheels 6 rotate reversely and at the same speed, their centrifugal force in J the vertical direction is 'eifective and in the horiin the above described manner.

other. These intermittent upwardly and down wardly directed centrifugal forces move the grate As the grate is elastically supported and balanced by the springs,

only a very small driving power is required therefor. In order to support the desired movement of the grate, the lower longitudinal supports 3 are inclined towards the rear.

The hoppers iii are in the construction of Figs. 5 and 6 firmly connected with the grate frame so that they participate in the movement of the grate. The hopper walls therefore require very little inclination. Outlet tubes M are fian'ged and connected with the hoppers and are immersed in the water of a clinker removing apparatus It: so that while the ashes falling through the grate are constantly removed an airtight seal is maintained. The forced draught enters through the lateral air-boxes l6 and, is led by the side plates ll thereof under the grate. The grate is hermetically closed towards the lower part by metal vsheets it! which are connected with the longiconnected to the same, fixed supports securing the springs at points between their ends, and rotatable eccentric means operatively connected with said first named supports so as to impart to the latter and the grate bars upwardly and downwardly directed thrust movements having a slight horizontal component, the said movement of the first named supports actuating the grate in the manner indicated.

2. In a mechanically moved grate, a set of grate bars, supports for said grate bars, semi-elliptic plate-springs for supporting the. said supports of the grate bars in an approximately horizontal position, one end of each of the plate-springs being rigidly secured to one of the supports of the grate bars while the other end is connected by links to the said support, fixed supports securing the plate-springs at points between their ends, and rotatable eccentrics operatively connected with said supports for the grate bars so as to impart to the supports upward and "downward thrust movements transversely to their longitudinal direction and with -a slight horizontal component, the said movement of the supports actuating the grate bars in the manner indicated.

3. In a mechanically moved grate, a set of grate bars, upper supports for the grate bars. lower supports rigidly connected with the upper supports, springs wholly supporting the upper supports in an approximately horizontal position, two shafts mounted on the lower supports and rotatable in an inverse sense, eccentric masses secured to the shafts in such a manner that they swing upon rotation of the shafts vertically in the same direction and horizontally in opposite direction and impart to the said lower and upper supports and grate bars as a unit upwardly and downwardly directed thrust movements having a slight horizontal component.

4. In a mechanically moved grate, a set of grate bars, supports for said grate bars, plate springs for freely supporting the said supports in an apzontal direction these forces counter-act each proximatelv horizontal position so as to be able .to swing freely upwardly and downwardly in its approximately horizontal position, and vibratory driving means operatively connected with the said supports and acting in an approximately vertical direction for imparting to the supports and grate bars as a unit upwardly and downwardly directed movements having a slight horizontal component,

the said movements of the supports and grate bars actuating the grate in the manner indicated.

5. In a mechanically moved grate, a set of grate bars, supports for said grate bars, semi-' elliptic plate-springs for supporting the said supports oi. the grate bars in an approximately horizontal position, one end of each of the platesprings being rigidly secured to one of the supports of the grate bars while the other end is connected by links to the said support, fixed supports securing the plate-springs at points between their ends, lower supports arranged below the supports of the grate bars and rigidly connected to these supports,. shafts rotatably mounted on the said lower supports, gear wheels on the shafts coupling the latter with one another, and eccentric masses arranged on the shafts in such position, that they swing upon rotation of the shafts synchronously upward and downward and impart to the lower supports, the supports for the grate bars and the grate bars upward and downward movements transversely to their longitudinal direction and with a slight horizontal component.

6. In a mechanically moved grate, a set of grate bars, supports for the grate bars,plate springs wholly supporting at least one end of each of the grate bar supports, fixed supports for securing said springs, and eccentric means for imparting movement-to the first named supports of the grate bars whereby the latter are caused to move upwardly and downwardly in an oblique direction on the said supporting springs, the said move BERNHARD mam. 

